Centering mechanism

ABSTRACT

The centering mechanism and method described herein are used for locating objects with respect to a center line or to a center. The mechanism includes opposed centering members for engaging opposite sides of an article to be centered so as to grip the article as a part of an assembly including a gauging element which is differentially positioned in accordance with the measured dimension of the article. The assembly is then moved with the article in a given direction to engage the gauging element with a stop at which time any article within a given range of sizes will be located in position with its center on a center line previously determined or with its center at a center point which has been previously determined.

United States Patent 1 Anderson Nov. 6, 1973 CENTERING MECHANISM [75]Inventor:

[73] Assignee: Brex Corp., Trustee, Los Gatos,

Calif.

[22] Filed: Sept. 7, I971 {21] Appl. No.: 178,077

OTHER PUBLICATIONS American Machinist, Nov. 8, 1933, pp. 732-733 r nsmtkqsQQEQSLQQHFL Primary ExaminerWilliam D. Martin, Jr. AtlorneyAllen &Chromy 57] ABSTRACT The centering mechanism and method described hereinare used for locating objects with respect to a center line or to acenter. The mechanism includes opposed centering members for engagingopposite sides of an article to be centered so as to grip the article asa part of an assembly including a gauging element which isdifferentially positioned in accordance with the measured dimension ofthe article. The assembly is then moved with the article in a givendirection to engage the gauging element with a stop at which time anyarticle within a given range of sizes will be located in position withits center on a center line previously determined or with its center ata center point which has been previously determined.

6 Claims, 25 Drawing Figures PATENIEDNM ems i 3.769.714

SHEET 1 [IF 9 I FIG.2

INVENTOR.

EARL R ANDERSON ATTORN EYS PATENTED Ni]? 6 I973 Sh'EET 2 BF 9 INVENTOR.EARL R. ANDERSON ATTORNEYS PAHNIEnmv 6 I975 3,769,714

SHEETMCF 9 FIG.9

INVENTOR. EARL R. ANDERSON PATENIED HHY 6 I973 SHEET 7 BF 9 FIG.|5

IG-v !9 FIG.

INVENTOR. EARL R. ANDERSON FIG. I8

' ATTORNEYS PATENIEBnuv 6 1973 3,769,714 I sum 8 BF 9 H lo lllb' lu'cSTATION I EASTATION? STATION 3 CENTERING MECHANISM DESCRIPTION OF THEINVENTION The present invention relates to centering devices and methodswherein a series of objects providing ranges of sizes of a givenvariety, for example, field run apples, field run pears, or field runpeaches, can be centered by the centering means then moved to one ormore points of operation where the center of the object will always beat a given location or in some cases on a given center line.

It is a general object of the invention to provide an improved means andmethod for automatically centering articles of a given type.

It is a further object of the invention to provide an improved methodfor accomplishing the centering of an article.

A further object of the invention is to provide a centering means whichoperates on a track or path and has opposed centering devices slidablealong the track independently of each and adapted to have articles ofbelow a given size positioned therebetween for centering.

Another object of the invention is to provide centering means of theabove character wherein opposed article engaging members operate tocenter the articles transversely of the track or paths.

A further object of the invention is to provide means for automaticcentering of devices with a plurality. of centering locations where asuccession of operations can be performed each of which requirescentering a device with respect to the same center or axis.

Still another object of the invention is to provide a centering assemblywhich will receive an object between centering members with thedimension to be measured or centered extending between the members andalso including a gauging element which is moved .along a course or pathin the process of centering the object between the members, so that theentire assembly with the object therein can be moved to a position wherethe gauging element will encounter a previously determined or locatedcenter stop and thereby locate the object or article with respect to itscenter or center line. I

Still another object of the invention is to provide a method by which agauging element is positioned in accordance with a certain selecteddimension of an article, such as a diameter for example, and thereaftercan be used as part of an assembly in locating the center of thedimension or diameter with respect to any selected centering stop orstops.

The above and other objects of the invention are attained as describedin connection with a description of a preferred embodiment thereof inwhich:

FIGS. 1-5 illustrate one preferred form of the invention.

FIG. 1 is a perspective view of one form of the invention;

FIG. 2 is a fragmentary sectional view taken in the plane indicated bythe line 2-2 in FIG. 1;

FIG. 3 is a schematic plan view illustrating a condition of the partsduring starting ofthe centering operation;

FIG. 4 is a view similar to FIG. 3 at a subsequent position of thecentering operation;

FIG. 5 is a view similar to FIGS. 3 and 4 but showing parts in positionwhen the article is finally located on the center line;

FIGS. 6-8 illustrate a second preferred form of the invention;

FIG. 6 is a schematic plan view showing the article located between twocentering members but not engaged therewith at the beginning of thecentering operation;

FIG. 7 is a view similar to FIG. 6 but showing the members as they beginto move along a track with the article engaged between the centeringmembers;

FIGS. 8 and 8a are views similar to FIGS. 6 and 7 but showing thearticle just before and just after it has arrived at a center position;

FIGS. 9, l0 and 11 show a third preferred form of the invention whereinthe article in addition to being moved to a center line is actuallymoved to a location at a center point;

FIG. 9 is a perspective view showing a third preferred form of theinvention.

FIG. 10 is a view showing the centering members spaced apart already toreceive the object to be cen tered;

FIG. 11 is a plan view similar to FIG. 10 showing the parts where onecentering member has been released and moved to centering position;

FIG. 12 is a plan view showing both article centering members havingtheir centering elements moved to active position; I v I FIGS. 13-20illustrate a fourth preferred form of the invention;

FIG. 13 is a perspective view of the centering apparatus;

FIG. 14 is an exploded perspective view illustrating the details andarrangements of the various elements of the centering mechanism;

FIGS. 15-18 are schematic operational views illustrating the operationof thelcentering mechanism;

FIG. 19 is a detail section taken on the line 19-19 in FIG. 15;

FIG. 20 is a detail section taken on the line 20-.-20 in FIG. 18;

FIG. 21 is a schematic perspective viewof a double unit centering meansmounted on guid'ejtracks for operation'on an object having portions ofdiffering diameter;

FIG. 22 is a perspective view illustrating the use of the unit shown inFIG. 21, for example in a pear stemmin'g, seed celling and splittingoperation;

FIG. 23 is a schematic diagrammatic view illustrating the use of theunit shown in FIG. 21 with a walnut, for example, where it is desired tohave the walnuts with the same ends facing the same direction; and

FIG. 24 is a diagrammatic view of another form of centering deviceoperating on the same principle as those previously described butemploying a gear and rack mechanism.

Referring first to FIGS. 1 through 5, the centering means includes abase 20, in which parallel guide grooves or tracks 21 are provided.These guide grooves or tracks receive and provide a path for respectiveopposed centering members 22 and 23, each of which includes an uprightcentering element or wall 24 and 24a,

respectively. The member 22 and its wall 24 are carried by a runner orslide 25 which is received for sliding movement in the groove 21.correspondingly, the

member 23 and its wall 24a are carried by slide 25a in the groove 21.

Associated with these centering members 22 and 23 is an auxiliarycentering indicator 51 (FIGS. 1 and 2) which includes a movably mountedplate 52 carried by a pair of parallel links 53'having one set of endspivoted to the base plate 20 and the other to the centering plate 52.The plate 52 carries a straight line motion mechanism including asupporting lever 54 pivoted at 55 on the plate and'its other end at 56to an actuating lever 57. The actuating lever 57 has its free endprovided with a pin or a roller 58 engaged and captivated by a notchedstop member 59 carried by the centering element 24a. i

A control lever 41 is pivoted to the actuating lever 57 at its midpointand lever 41 is also pivotally secured at 42 to the plate 52. The lever41 extends through a slotted stop bracket member 43 carried by the plate52 and also embracing and serving as end stops for the end of the lever57. The pivotal pin 45 of the connection of lever4l with the center ormidpoint of the lever 57 also carries a gauging element or roller 44which by virtue of the mounting of the actuating lever 57 on the levers54 and 41 will move in a straight line parallel to the grooves 21. Alsothe pin 58 at the end of the lever 57 will be caused to move in astraight line when it is actuated by the centering element 24a. Atension spring 46 extends from the pin 43 mounting the gauge roller 44to a suitable pin on the base 20. This spring 46 urges the plate 52against a stop 47 on the base 20 and correspondingly through the pin 57determines an initial position of the centering element 240, i.e., itsopen or article receiving position. The top of the stop bracket 43 maycarry a scale reading from 4 to to show in inches the total range ofmovement of the pin 58.

The lever 57 (FIGS. 1 and 3) ispart ofa motion reducing mechanism andits midpoint including the gauging element or roller 44 will move onehalf of the distance moved by the pin 58 carried at the end of thelever. The end of the lever moves along aone-to-one scale on the stopbracket 43 while the center of the lever and the gauging element 44 movewith respect to a stop 48. A fixed stop 49 (FIGS. land 3) on the member22 limits the movement of the stop bracket 43 and of the movable plate52. An actuating lug 50 on the runner 25 is aligned with the plate 52 topick the plate up for movement during the sliding operation of therunner 25.

In operation the centering elements 24 and 24a are spaced apart amaximum amount for a particular size of the mechanism to receive anarticle therebetween at a definite location, for example, the article Ain FIG. 3. At this time neither the two-to-one lever 57 nor thegaugingelement 44 have been moved from their initial position.

As the centering element 24a is moved manually to its right from theposition shown in FIG. 3 to the position shown in FIG. 4 the stop 50 onthe runner 25 moves from its inactive position shown in FIG. 3 to engagethe plate 52 while this plate is still held by the spring 46 against thestop 47. The movement of the centering element 24a and 24b, the lever 57and the centering element 24a. This condition of the parts continuesuntil element A is engaged between the respective centering elements 24aand 24 as shown in FIG. 4. At this time the pointer 40 which is carriedby the centering element 24a has been moved to the beginning of a scale39 on the base 20.

Subsequent pushing movement of the centering element 24a toward theright in FIG. 4 will result in moving the entire assembly to theposition shown in FIG. 5 when the gauging element 44 engages its stop48. The movement of the gauging element 44 and the lever 57 from theposition shown in FIG. 4 to that shown in FIG. 5 is a bodily movementwith plate 52 and is at the ratio of 1-2 to the prior prodding movementof lever 57. The actual amount of movement and its transmission to theassembly is carried out by the movable plate 52 which is bodilydisplaced from position shown in FIGS. 3 and 4 to position shown in FIG.5. It will be noted that the right hand end calibration of the scale 39is marked CL (for center line) and center and'center line of the elementA along its dimension being measured has been placed on this center lineby movement from the position of FIG. 4 to the position shown in FIG. 5.It will be seen that the gauging element is moved along a course or pathfrom its position shown in FIG. 3 to the final position shown in FIG.5'. During the first portion of this movement it is controlled by thecentering element 24a acting on the pin 58 carried by lever 57. Thisone-to-one drive action continues until the article A is engaged betweenthe centering elements 24 and 240. As a result. the position of thegauging element 44 under this action has been controlled by distanceX-A, where X represents the space between the adjacent vertical surfacesof the'centering elements 24'and 24a and A is the dimension of thearticle being measured. Because of the two-to-one reduction of motionbetween pin 58 and gauging element 44 this has been reproduced inhalfscale in the spacing between the gauging element 44 and its stop 48.At the time that the article A is engaged by the'centering element 24,the cent tering element 24a will have moved a distance of X minus A andthe gauging element 44 will have moved X-A/2. Thereafter the centeringelement 24 will be gauging element 44 from the position shown in FIG. 3

to the position shown in F IG. 4 is all accomplished by the movement ofthe centering element 24a through the pin 58 in lever 57 so that anymovement of the parts has been on a on'e-to-one ratio with the movementof picked up and driven with the element A and centering element 24astarting the movement of .the drive projection 50 on the runner 25toward the end of stop bracket 43 on the plate 52. At the time that theplate 52 starts its motion the amount it can move will be determined bythe spacing of the gauge element 44 from its stop bracket 48 so that thesubsequent movement of the assembly will be on a one-half scale, i.e.,one-half of the distance A- or one-half of the dimension being centered.

Subsequent movement of the assembly with the gauging element 44 sopositioned results in the entire assembly moving for a-further distancewhich is one-half of the dimension of A because it is engaged byone-half scale movement of the gauging element 44 or roller 44 withrespect to its stop 48.

In the operation of the apparatus shown in FIGS. 6, 7 and 8 the partsare essentially the same'as described above except that the pin 58 isnot captivated by the member 59 but is merely aligned with the member59a for pushing movement thereby. In FIG. 6 an object B is placedbetween the centering members 24 and 24a whichare placed at anyconvenient location along the track. In FIG. 7 the centering element 24ahad been moved to the right to pick up the article Band through it thecentering element 24 so that the position of the actuating member 59awith respect to the centering element 24 has been adjusted or determinedby the dimension of the article B upon which it is to be centered. Alsothe centering element 24 and its runner 25. which carries the stop 50have been preset in the position of the stop 50 with reference to theplate 52 at the time that the actuating projection 59a on the centeringelement 24 will contact the pin 58.

The modification of the invention illustrated in FIGS. 9 through 12shown is an embodiment which can be op tionally used as a center linelocator or as a center point locator, operating generally on the sameprinciples as the modification shown in the preceding figures.

In'general, the centering elements of the modification of FIGS. 9through 12 have two parts in telescoping relation, one operatingidentically as the line centering elements previously described and theother being of V-shape'contour so as to-center anelement transversely ofthe tracks in which the centering elements are mounted. v

The centering element 124 (FIGS. 9 and 10) includes a pair of supportshafts 131 which extend rearwardly from the front face of element 124and pass through apertures in a frame member 132, having respectivesprings 133 placed about each rod 131 and abutting the member 132 at oneend and a washer 134 at the other. The springs 133 are normallycompressed and held in position by means of a lock pin 136 carried by arearwardly extending member 137 from the plate 132, this latch memberhaving at its rearward end a latch 138 (FIG. 9) which engages over alatch 139 on the base plate so that the entire assembly is heldretracted, and element 124 can be advanced as seenin FIG. 10 where itsfront face overlies the V-shaped transverse centering element 141. Thiscentering element is carried by the plate 132 and is movable therewith.

As seen in FIG. 11, the left hand centering assembly including member124a and the centering element 141a, are in their released'position, itsstop pin 136a having been pulled free of its corresponding lockingaperture 140. Thus the centering member or element 141a is in activeposition and will operate on a round member or half roundmember'when'engaged therewith, the other side being engaged by thevertical'centering wallof a centering element 124.

In FIG. 12 the pin 36a has been moved from the rearwardly extendingmember 37a and placed in the aperture 44 provided for storing it when itis inactive.

In FIG. 12 both transverse centering elements 41 and 41a have both beenadvanced to active position in the manner described above inconnectionwith the member 141a.

In order to resiliently engage any article between the two centeringmembers 124 and 124a, the spring 148 extends between a fastening element149 on the plate 23, and an eye 147 projecting out from the member Themodification shown in FIGS. 9 through 10 operate generally as describedin connection with the preceding modifications as Iong as the parts are.conditioned as shown in FIG. 10. However, with the parts positioned inFIG. 11 one of the centering elements 141a has been made active so thatit will tend to center atriangular or half round object transversely ofthe guide rails and transversely of the longitudinal centering elementor motion. In FIG. 12 one of the transverse centering elements 141 and141a is projected so that they will operate on any square or roundarticle placed therebetween so as to center it not only longitudinallyin accordance with the operation previously described but alsotransversely by virtue or the V-shape of the transverse centeringelements 141 and 141a.

FIGS. 13 through show another form ofa centering mechanism whichincludes a main base or frame including a center stop plate (FIGS. '13and 14) having secured thereto a pair of opposed rails or track members71 and 72. The plate 70 has an opening therein of a total length andhaving its ends formed by stop edges or lines 73-and 74, respectively,which will be referred to hereinafter. The side rails 71 and 72. areeach cut away to a form recesses adjacent the base plate 70 to providerespective guide grooves 75. Engaging in the guide grooves 75 are therespective side edges 76 of a ment' along the tracks and the slot 8l'isdisposed at an plate 77 which has secured thereto a pair of groovedguide members or tracks 78 and 79, the center. portion of the plate 77having a centering slot 81 formed therein at an angle of 30 to the sidesof plate 77 which slot 81 will be referred to hereinafter. At one endthe guide rails 78 and 79 have secured thereto a transverse centeringmember 82 having a V-shaped centering recess 83 in one face and carryingspring-urged balls 84 which may seat in respective shallow depressionsor seats 86 in respective side rear plate 87 carried by side rails 71,72. I I

A second centering member including a base plate 91 (FIGS. 13 and 14)has its side edges engaged with the grooves of the guide rails 78 and 79and at one-end has a centering element 86 secured thereto with the V-shaped center recess 87 facing the V-shaped centering recess 83 andcentering element 82. The plate 91 also has an'inclined slot 92 which isat an angle to and overlaps the slot 81 and also the opening defined inpart by the stop walls 73 and 74., A size indicator pin or gaugingelement 96 is provided having a flange portion 96a attached theretointermediate the ends of pin 96, the lower end'of pin 96 (FIG. 19) isengaged'with the slot 81 in the plate 77 and having its upper endengaged in the slot 92 of plate 91. The flange 96a overlaps the edges-ofthe slots 91 and 92 so that the pin'portio'n rides freely in the slot81and is also long enough to engage within the opening formed in part anddefinedas to length by the stop walls 73 and 74. 1 I

The partsare so dimensioned and related so that the gauge pin 96 (FIG.15) is engaged with the ends the slots 81 and 92 with the centeringelements in their full open position to receive the maximum diameterarticle to be centered and the position of the gauge pin 96 isdetermined by the relatively longitudinal displacement of the respectiveplates 77 and 91 and slots 81' and 92.

In the modificationsshown in FIGS. 13 through 20 the slot 92 is disposedat an angle of 60 to the moveangle of 30 to the same line so that thetwo slots are perpendicular. 7

Also the angle of each of the stop surfaces 73 and 74 is 60 with respectto the longitudinal center line. In general the length of the slots 81and 92 must be such that the gauging pin 96 is always stopped by one ofthe stop surfaces 73 or 74 rather than by an end of one of the slots.The particular angles used are merely illustrative and other angles canbe employed.

The operation of this centering means will be described starting withFIG. 15 where the two centering members 82 and 86 are spread theirfurthest distance apart, and the pin 96 is at the respective ends of theslots 81 and 92 as described above and also against the inclined stopwall 74 in the bottom plate 70. In this condition of the parts the upperslide 91 containing the slot 92 with its centering element 86 is free tomove, and the centering element 82 and the slide 77 containing the slot81 is yieldably latched in position by spring pressed balls 84 andlatching notches 86. The slots 81 and 92 are approximately at rightangles to each other and the lengths of the slots are sufficiently longto allow the stop walls 73 and 74 to function. The object A to becentered is shown engaged with the V-notch 87 and as supported on theplate 91. The centering member 86 is moved to the right as seen from theposition shown in FIG. 15, to the position shown in FIG. 16 to engagethe object A in the opposite notch 83 so that the two centering elementsand the object bear a fixed determined relation to each other. Also thepin 96 is in a predetermined location in both'of the slots 81 and 92having a direct proportioned relation to the diameter of the object A tobe centered. The pin 96, the centering elements 83 and 87 and the objectA comprise a center 10' eating assembly and can be moved as an assemblyto a center position as located by a predetermined center line stop suchas stop surfaces 73 and 74.

The next operation is to disengage the latch pins 84 from the latchingdepressions 86 and move the entire center locating assembly to the righton the base from the position shown in FIG. 16 to the position shown inFIG. 17 when the pin gauge element 96 will be engaged with the righthand terminal wall or stop 73 of the bottom opening in the plate 77.When this is done the center of thearticle will be aligned with thecenter index mark 97. Thereafter the entire center locator assembly andthe article can be moved to the left as seen in FIG. 18 until the pin 96engages the opposite wall 74 when the center of the article will bealigned with a center index marked 98.'

The particular location of the center line stops and the size range'ofthe article can'be determined by selecting certain parameters for agiven mechanism. AS

shown in the drawings herein in the first three modifications themaximum opening between the centering elements 24 and 24a isapproximately 4" from plane surface to plane surface and the center linestop 43 bears a fixed relation to and is a fixed distance from the gaugeelement. In the modification shown in FIGS. 13-20 the maximum dimensionor diameter of a circular object to be centered is 4" andthe minirnum isl'f which is the smallest circle that can contact the centering notches83 and 87with the plane opposed surfaces of the centering elements 124and 124a engaged.

1 The location of the center stop lines or walls and their angularitycan either be computed or can be laid out graphically from the assumedparameters, this being enabled by the fact that the transverse positionof the gauging element or pin 96 is representative of the center of eachof the varying diameters within the range selected. The fixed locationof and the spacing apart of the center line stops 73 and 74 (FIG; 14) isa matter of convenience to the particular problem involved. Also thenumber of center line stops is a matter of selection. It is thegeometrical relation between the elements of the center line assemblyincluding the pin 96 which makes the line or wall 73 a center line stopand this line can be placed at any desired location along any desiredpath as long as the geometrical relation between the center linelocation and the center line stop is not changed.

Referring to the modification shown in F IGS. 13-20 the center pin orgauging element96, apart from its control by the respective slotsengaging it, is freely movable and is positioned by the slots 81 and 92.Its position is responsive solely to the movement of the centeringelements with respect to each other and to cause the movement of thecentering pin 96 in the slots 81 and 92. Once movement stops the gaugingelement or pin 96 is held captive or fixed in a differentially adjustedtransverse position which bears a geometrical relation to the centerline or center of the article being gauged and centered, and the centercan be located at any desired position by positioning gauging element96.

Referring to FIGS. 21, the mechanism includes a pair of centeringdevices 100a and l00b similar to the ones described in connection withFIGS. 13 through 20. These two centering elements have their frameportions 71b and 71a joined by a rectangular apertured frame 101 securedthereto and holding the two units 100a and l00b in spaced apart parallelrelation in mirror image fashion, with the centering elements 82b, 86band 82a, 86a projecting at right angles to the plane of their supportingplates so as to be superposed with respect to each other as respectivepairs and to be in vertical alignment with each other as far as theirstarting and finishing positions are concerned. The bottom frame pieces71a and 71b embrace the pair of tracks 102 and 103 which are connectedby a supporting plate 104. These tracks serve to guide the unitcomprising members 10a, 10b, and 101 longitudinally along a path whichmay be straight, circular or any shape desired.

It will be seen that the upper members 82b and 86b will center one endof an object, while the lower centering elements 82a and 860 will centerthe opposite end of the object so that any object will be centered alonga longitudinal center line. It will be recalled in operation thecentering elements 82b, 86b and 82a, 86a will always center an objectand can then be employed to move the center to a fixed predeterminedposition and in the present case with the two units 100a andl00b-together these predetermined positions coincide for'respectiveupper and lower pairs of lowering elements. Q

This will be useful in centering elements such as fruit which has oneend larger than the other, for example, Delicious apples, pears,peaches, apricots, and with nuts such as walnuts, pecans, etc., and withcertain machine elements, for example, with a cone shaped element or acylindrical shaped element which has two different diameters'and whereit is desirable to center the element for a machining operation. I

As illustrative of the use of the centering mechanism of FIGS. 13through 20, particularly as illustrated, for example, in FIG. 21,reference is made to FIG. 22 where there are three stations 1, 2 and 3along a track 102, 103 and having respective releasable stops 111, 111a,and lllb of conventional design.

At station 1 when the pear has been aligned by both the upper set ofcentering elements 82b and 86b and the lower set of centering elements82a and 864 which as seen as engaging the larger bulb end of the pear,this alignment of the pear by the two sets of centering elements ispreferably effected by employing lower two elements 82a & 86a to centerthe bulb end of the pear,

and at the same time effecting a general centering of the upper end ofthe pear. Then the upper members 82b and 86b are operated to center theupper end of the pear. Thereafter the two sets of centering elements82a, 86a and 82b, 86b are moved together to a desired center location,i.e., against a stop, the pear is aligned with the longitudinal axis inalignment with a coring or stemming tube 112 which has a pin 1 13 forengagement with a stop 114. The stemming tube 112 may be of any desiredtype usually associated with the'stemming of pears and serves to cut outa cylindrical segment from the center thereof. Subsequently, thecentering unit comprising the members 100a, 100b, and 101 is moved alonguntil the stop engages the stop 11 lb when the tubular opening in thepear will be aligned with and above a seed cellingknife 116 having a pin1 17 thereon for engaging with an adjustable stop 118. The stop 118 ismoved up and down in accordance with the diameter of the bulb end of thepear so that the seed celling knife 116 will be adjusted to seed celland remove the core from the center of the bulb end.

After these operations are completed, the unit 100a, 101 is moved intoengagement with stop lllc where its longitudinal axis is aligned with asplitting knife 119 which can be moved downwardly in usual fashion tosplit the pear into the number of segments desired.

It will be understood that thevarious elements of a pear processingmachine as shown are all conventional and may be in any form desired forthe particular pear preparation application, and the peel may be removedinitially, for example, by lye treatment or it may be peeled, forexample, between the seed celling operation and the splitting operation.

Referring to FIG. 23 there is shown a use of the unit such as shown inFIG. 21 where the upper centering elements 86b and 82b are engaged withthe small end of a walnut W and the lower centering elements 86a and821; are engaged with the large end of the walnut. From the differencein movements of the centering elements to engage with large and smalldiameters of the walnuts it appears that the walnut W was placed in thecentering elements at the left of the FIG. 23 with its large endlowermost, and it therefor can be rotated 180 to place the large enduppermost. If, .when the walnut was placed in the centering elements asshown'at the left of FIG. 23 the upper centering elements 82b and 86bmove less than the lower centering elements 82a and 86a to engage thewalnut then the walnut would be ascertained to be with the large enduppermost and no rotative movement is necessary. It would be seentherefore that where it is desired to position elements havingrespective large and small ends with the large end in a v givendirection, they can be fed indiscriminately into the centering elementassembly, insofar as their ends are concerned, and then those which havethe small end uppermost can be rotated 180 to place their large isengaged by a spring pressed pin 129 to hold the slide resiliently inthis position. The two gear racks 126 and 127 are of the same pitchdiameter and size to engage a pinion 131. journaled freely about itscenter supporting shaft 132 in a slide 133 carried in a track 134parallel to the tracks 125. Opposite each end of the center slide 133 apair of opposed stops 137 and 138 are provided as center stop so thatthe racks 126, 127 may be moved from the position shown in thelefthand'portion of the view where the centering elements-121,122 are inwide open position and can take the largest size of article to becentered. In the middle view in FIG. 24 both of the gear racks 126 and127 and the gear 131 have all been moved from the positions shown inFIG. 24a to engage an article to be centered and moved to a centerposition. Subsequently, the unit comprising the two centering elements121, 122, the gear racks 126 and 127, the gear 131 and the slide 133 aremoved as a unit in this instancetoward the bottom of the sheet.-

' ilar parts of the article can be positioned in engagement with the twocentering elements. Obviously, the centering elements couldbe of theform shown in connection with the other modifications in FIGS. 1 through10 where a planar centering element may be employed.

With respect to all of the modifications shown herein including the onesshown in FIGS. 1 through 10, the ones shown in FIGS. 11 through 20, andthe' ones shown in FIG. 24, it will be'appreciated that the stops whichstop the assembly with the article located on center could be madeadjustable in either direction from this position, for example,.stop 138could be adjustable up and down from the position shown for'a selectedamount so that the article might be placed with its center a fractionalmeasurement above or below the center line. v I l 7 While I haveshownandwdescribed a preferred embodiment of the invention, it will beunderstood that the invention is capable of variation and modificationfrom the form, shown so that the scope thereof should be limited only bythe proper scope of the claims appended hereto. v I I 1. In a center orcenter line locator, a pair of centering elements mounted for movementto grip an article therebetween, a gauge setting member, means pivotallymounting said'member on a movable plate, one of said centering elementshaving means moving said member, a second gauge setting member movablewith the other of said centering elements, a gauge element controlled byboth of said gauge setting members means responsive to themovement ofboth of said setting members moving said gauge element to a positioncorresponding to a center or center line position of an article engagedbetween said centering elements. l

2. In a center or center line locator as recited in claim 1, in whichthe gauge element comprises a pin or roller, 21 movably mounted levercarrying the pin or roller, and in which the first gauge-setting membercomprises means on the first centering element and engageable with thefree end of said lever, and the second gauge setting member comprises anelement movable with said second centering element for moving the leverbodily with its mounting means.

3. In a center or center line locator as recited in claim 1, in whichthe gauge element comprises a freely movable pin, in which the firstgauge setting member comprises means providing a first inclined camslot, and in which the second gauge setting member comprises a secondmeans providing a second inclined cam slot in intersecting relation withsaid first slot, the cam slots engaging said pin and being movablerespectively with said centering elements.

4. ln a center or center line locator as recited in claim 1, in whichthe gauge element comprises a pinion, translationally movable mountingmeans upon which the pinion is journaled, and in which the respectivegauge setting members comprise racks connected respectively to saidcentering elements and both engaged with said pinion but on oppositesides thereof, and means mounting said racks for movement parallel tothe movement of the mounting means for said pinion.

5. ln a centering device, a frame, a center indicating a gauge elementmounted for movement on said frame, and a pair of opposite centeringelements movable with respect to each other and said gauge element andbeing operative to engage an article positioned therebetween, each ofsaid centering elements having means related thereto and to said gaugeelement, said last mentioned means responsive to relative movementbetween said elements to control the position of said indicating elementto indicate a dimensional measurement of the article as measured by saidcentering elements.

6. In a center or center line locator, a base, a pair of opposed articlecentering elements mounted for movement on said base, said centeringelements being responsive to an article engaged therebetween to spacesaid centering elements apart differentially in accordance with and inproportion to a selected dimension of the article, a stop on said base,and a mechanism responsive to the differential positioning of one ofsaid centering elements in accordance with the selected dimension of thearticle, said mechanism including a gauge element, means differentiallypositioning said gauge element with respect to said stop so that saidgauge element bears a fixed geometrical relation to the center line ofthe article, whereby engagement of said gauge element with said stoppositions the article and the centering elements with reference to acenter line with the center of the article positioned on the centerline.

1. In a center or center line locator, a pair of centering elements mounted for movement to grip an article therebetween, a gauge setting member, means pivotally mounting said member on a movable plate, one of said centering elements having means moving said member, a second gauge setting member movable with the other of said centering elements, a gauge element controlled by both of said gauge setting members means responsive to the movement of both of said setting members moving said gauge element to a position corresponding to a center or center line position of an article engaged between said centering elements.
 2. In a center or center line locator as recited in claim 1, in which the gauge element comprises a pin or roller, a movably mounted lever carrying the pin or roller, and in which the first gauge-setting member comprises Means on the first centering element and engageable with the free end of said lever, and the second gauge setting member comprises an element movable with said second centering element for moving the lever bodily with its mounting means.
 3. In a center or center line locator as recited in claim 1, in which the gauge element comprises a freely movable pin, in which the first gauge setting member comprises means providing a first inclined cam slot, and in which the second gauge setting member comprises a second means providing a second inclined cam slot in intersecting relation with said first slot, the cam slots engaging said pin and being movable respectively with said centering elements.
 4. In a center or center line locator as recited in claim 1, in which the gauge element comprises a pinion, translationally movable mounting means upon which the pinion is journaled, and in which the respective gauge setting members comprise racks connected respectively to said centering elements and both engaged with said pinion but on opposite sides thereof, and means mounting said racks for movement parallel to the movement of the mounting means for said pinion.
 5. In a centering device, a frame, a center indicating a gauge element mounted for movement on said frame, and a pair of opposite centering elements movable with respect to each other and said gauge element and being operative to engage an article positioned therebetween, each of said centering elements having means related thereto and to said gauge element, said last mentioned means responsive to relative movement between said elements to control the position of said indicating element to indicate a dimensional measurement of the article as measured by said centering elements.
 6. In a center or center line locator, a base, a pair of opposed article centering elements mounted for movement on said base, said centering elements being responsive to an article engaged therebetween to space said centering elements apart differentially in accordance with and in proportion to a selected dimension of the article, a stop on said base, and a mechanism responsive to the differential positioning of one of said centering elements in accordance with the selected dimension of the article, said mechanism including a gauge element, means differentially positioning said gauge element with respect to said stop so that said gauge element bears a fixed geometrical relation to the center line of the article, whereby engagement of said gauge element with said stop positions the article and the centering elements with reference to a center line with the center of the article positioned on the center line. 